In a motion control system such as a machine tool, a semiconductor manufacturing device, and an industrial robot, in which a highly precise operating motion using a plurality of axes is required, a motion controller and a plurality of controlled axes need to operate in synchronization with each other.
A technique has been proposed for a conventional motion control system, in which the same interpolation command is input to a plurality of motion controllers, and the motion controllers generate servo position commands or servo torque commands for a plurality of servo drives at slightly different timings from each other and transmit the commands to the servo drives, in order that even a multi-axis interpolation command, which cannot be processed with a desired control cycle by a single motion controller, can still be output to the servo drives with the desired control cycle (see, for example, Patent Literature 1).
According to the technique described in Patent Literature 1, in a motion control system in which a motion controller and a plurality of servo drives are connected by a high-speed serial bus or serial communication that does not have a synchronous communication function, the motion controller outputs a motion command to the servo drives by a start-up interrupt at set time intervals and outputs a time-clear request to the servo drives by a start-up interrupt that is delayed by a set time from the output of the motion command. The servo drive delays execution of the time-clear request from the motion controller by a set time and clears the timer in the servo drive. With this configuration, the servo control processing is performed simultaneously in the servo drives.